The Ethernet Ring Protection Switching (ERPS) protocol is an industry standard and is specified within International Telecommunication Union ITU SG15 Q9, under G.8032 “Ethernet ring protection switching” (G.8032v1—2008, G.8032v2—2010, G.8032v3—2012, and G.8032v4—2015), the contents of which are incorporated by reference. ERPS specifies protection switching mechanisms and a protocol for Ethernet layer network (ETH) rings. Each Ethernet Ring Node is connected to adjacent Ethernet Ring Nodes participating in the same Ethernet Ring, using two independent links. A ring link is bounded by two adjacent Ethernet Ring Nodes, and a port for a ring link is called a ring port. The minimum number of Ethernet Ring Nodes in an Ethernet Ring is two. Two fundamental principles of G.8032 include a) loop avoidance and b) utilization of learning, forwarding, and Filtering Database (FDB) mechanisms defined in the Ethernet flow forwarding function (ETH_FF). Loop avoidance in an Ethernet Ring is achieved by guaranteeing that, at any time, traffic may flow on all but one of the ring links. This particular link is called the Ring Protection Link (RPL), and under normal conditions, this ring link is blocked, i.e. not used for service traffic. One designated Ethernet Ring Node, the RPL Owner Node, is responsible for blocking traffic at one end of the RPL. Under an Ethernet ring failure condition, the RPL Owner Node is responsible for unblocking its end of the RPL (unless the RPL has failed) allowing the RPL to be used for traffic. The other Ethernet Ring Node adjacent to the RPL, the RPL Neighbor Node, may also participate in blocking or unblocking its end of the RPL. The event of an Ethernet Ring failure results in protection switching of the traffic. This is achieved under the control of the ETH_FF functions on all Ethernet Ring Nodes. An Automatic Protection Switching (APS) protocol is used to coordinate the protection actions over the ring.
G.8032v2 introduced additional features, such as: multi-ring/ladder network support; revertive/non-revertive mode after condition, that is causing the switch, is cleared; administrative commands: Forced Switch (FS), Manual Switch (MS) for blocking a particular ring port; flush FDB (Filtering database) logic, which significantly reduces amount of flush FDB operations in the ring; and support of multiple ERP instances on a single ring.
G.8032 deployments have proliferated as it supports a simplified network architecture and enables fast protection switching. In actual deployments, there can be hundreds to thousands of Virtual Local Area Networks (VLANs) on a given G.8032 ring. With a large number of VLANs on a given ring, there can easily be misconfigurations such as missing a VLAN at a particular node, removing a VLAN from a node, etc. That is, the configuration of VLANs and G.8032 rings can include operator configuration leading to human errors. Unfortunately, there are no efficient misconfiguration detection techniques to notify the network operator prior to issues, e.g., broadcast storms, etc. Specifically, the misconfigurations may not exhibit problems under normal working conditions, but cause loops when there is a link failure and recovery. With hundreds or thousands of VLANs possible per node per G.8032 rings, there is a need for efficient G.8032 misconfiguration detection systems and methods.